A private branch exchange (PBX) is a telephone network that serves a business or an office. A virtual PBX (vPBX) allows a business or office to be served by a PBX system hosted on remote servers. The service can be provided through a combined voice network (e.g. telephone network) and data network (e.g. Internet). Call queuing is a feature that can support a large number of callers, allowing each to wait for an available queue agent to become accessible to assist them.